498 resultados para Dung beetles -- Australia, Northern -- Evolution.


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Four pollen and charcoal records derived from marine cores around the northern perimeter of Australia are examined to provide a regional picture of patterns, causes and impacts of climate change over the last 100-300 ka. The availability of radiocarbon dates and oxygen isotope records for the cores provides primary chronological control. Spectral analysis of components of these records demonstrates an overall importance of Milankovitch frequencies with clear glacial-interglacial cyclicity dominated by variation in precipitation. In addition, a number of pollen taxa, as well as charcoal particles, exhibit a 30 ka frequency that is considered, from its relationship with biomass burning and with results of past modelling, to reflect changes in the intensity of El Nino-Southern Oscillation (ENSO) variability. Pollen components of all records show a decline, frequently stepwise, in more fire-sensitive vegetation and its replacement with more fire-tolerant vegetation. There is some evidence that this trend is linked to an onset or general increase in ENSO activity and perhaps also to variation in monsoon activity dating from about 300 ka BP that was caused by changes to oceanic circulation within the Indonesian region. The trend may have accelerated within the last 45 ka due to burning by indigenous people. (C) 2003 Elsevier B.V. All rights reserved.

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Soil erosion is a major environmental issue in Australia. It reduces land productivity and has off-site effects of decreased water quality. Broad-scale spatially distributed soil erosion estimation is essential for prioritising erosion control programs and as a component of broader assessments of natural resource condition. This paper describes spatial modelling methods and results that predict sheetwash and rill erosion over the Australian continent using the revised universal soil loss equation (RUSLE) and spatial data layers for each of the contributing environmental factors. The RUSLE has been used before in this way but here we advance the quality of estimation. We use time series of remote sensing imagery and daily rainfall to incorporate the effects of seasonally varying cover and rainfall intensity, and use new digital maps of soil and terrain properties. The results are compared with a compilation of Australian erosion plot data, revealing an acceptable consistency between predictions and observations. The modelling results show that: (1) the northern part of Australia has greater erosion potential than the south; (2) erosion potential differs significantly between summer and winter; (3) the average erosion rate is 4.1 t/ha. year over the continent and about 2.9 x 10(9) tonnes of soil is moved annually which represents 3.9% of global soil erosion from 5% of world land area; and (4) the erosion rate has increased from 4 to 33 times on average for agricultural lands compared with most natural vegetated lands.

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Almost all leprosy cases reported in industrialized countries occur amongst immigrants or refugees from developing countries where leprosy continues to be an important health issue. Screening for leprosy is an important question for governments in countries with immigration and refugee programmes. A decision analysis framework is used to evaluate leprosy screening. The analysis uses a set of criteria and parameters regarding leprosy screening, and available data to estimate the number of cases which would be detected by a leprosy screening programme of immigrants from countries with different leprosy prevalences, compared with a policy of waiting for immigrants who develop symptomatic clinical diseases to present for health care. In a cohort of 100,000 immigrants from high leprosy prevalence regions (3.6/10,000), screening would detect 32 of the 42 cases which would arise in the destination country over the 14 years after migration; from medium prevalence areas (0.7/10,000) 6.3 of the total 8.1 cases would be detected, and from low prevalence regions (0.2/10,600) 1.8 of 2.3 cases. Using Australian data, the migrant mix would produce 74 leprosy cases from 10 years intake; screening would detect 54, and 19 would be diagnosed subsequently after migration. Screening would only produce significant case-yield amongst immigrants from regions or social groups with high leprosy prevalence. Since the number of immigrants to Australia from countries of higher endemnicity is not large routine leprosy screening would have a small impact on case incidence.

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The El Nino/Southern Oscillation (ENSO) phenomenon is believed to have operated continuously over the last glacial interglacial cycle(1). ENSO variability has been suggested to be linked to millennial-scale oscillations in North Atlantic climate during that time(2,3), but the proposals disagree on whether increased frequency of El Nino events, the warm phase of ENSO, was linked to North Atlantic warm or cold periods. Here we present a high-resolution record of surface moisture, based on the degree of peat humification and the ratio of sedges to grass, from northern Queensland, Australia, covering the past 45,000 yr. We observe millennial-scale dry periods, indicating periods of frequent El Nino events ( summer precipitation declines in El Nino years in northeastern Australia). We find that these dry periods are correlated to the Dansgaard - Oeschger events - millennial-scale warm events in the North Atlantic climate record - although no direct atmospheric connection from the North Atlantic to our site can be invoked. Additionally, we find climatic cycles at a semiprecessional timescale (, 11,900 yr). We suggest that climate variations in the tropical Pacific Ocean on millennial as well as orbital timescales, which determined precipitation in northeastern Australia, also exerted an influence on North Atlantic climate through atmospheric and oceanic teleconnections.

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This study examined whether people born in other countries had higher rates of death and hospitalization due to road crashes than people born in Australia. Data on deaths that occurred in the whole of Australia between 1994 and 1997 and hospitalizations that occurred in the state of New South Wales, Australia, between I July 1995 and 30 June 1997 due to road crashes were analyzed. The rates of death and hospitalization, adjusted for age and area of residence, were calculated using population data from the 1996 Australian census. The study categorized people born in other countries according to the language (English speaking, non-English speaking) and the road convention (left-hand side, right-hand side) of their country of birth. Australia has the left-hand side driving convention. The study found that drivers born in other countries had rates of death or hospitalization due to road trauma equal to or below those of Australian born drivers. In contrast, pedestrians born in other countries, especially older pedestrians had higher rates of death and hospitalization due to road crashes. Pedestrians aged 60 years or more born in non-English speaking countries where traffic travels on the right-hand side of the road had risks about twice those of Australian born pedestrians in the same age group. (C) 2003 Elsevier Ltd. All rights reserved.

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Targeting is increasingly used to manage people. It operates by segmenting populations and providing different levels of opportunities and services to these groups. Each group is subject to different levels of surveillance and scrutiny. This article examines the deployment of targeting in Australian social security. Three case studies of targeting are presented in Australia's management of benefit overpayment and fraud, the distribution of employment services and the application of workfare. In conceptualizing surveillance as governance, the analysis examines the rationalities, technologies and practices that make targeting thinkable, practicable and achievable. In the case studies, targeting is variously conceptualized and justified by calculative risk discourses, moral discourses of obligation and notions of welfare dependency Advanced information technologies are also seen as particularly important in giving rise to the capacity to think about and act on population segments.

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Using detailed Australian wool auction data we test for further evidence of pricing anomalies at sequential auctions. We find that an anomaly frequently exists and order is frequently endogenously determined. Moreover, prices increase through some sales and decrease through others. We examine whether it is possible to explain the variation in the anomaly across sales and conclude that there is no systematic relationship between the direction of the price anomaly and the characteristics of the wool or the auction. We do, however, find evidence that an anomaly, is more likely in longer sales.

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Objectives: To review changes in patterns of care for women with early invasive breast cancer in Western Australia from 1989 to 1999, and compare management with recommendations in the 1995 National Health and Medical Research Council guidelines. Design and setting: Population-based surveys of all cases listed in the Western Australian Cancer Registry and Western Australian Hospital Morbidity Data System. Main outcome measures: Congruence of care with guidelines. Results: Data were available for 1649 women with early invasive breast cancer (categories pT1 or pT2; pN0 or pN1; and M0). In 1999, 96% had a preoperative diagnosis by fine-needle aspiration or core biopsy (compared with 66% in 1989), with a synoptic pathology report on 95%. Breast-conserving surgery was used for 66% of women with mammographically detected tumours (v 35% in 1989) and 46% of those with clinically detected tumours (v 28% in 1989), with radiotherapy to the conserved breast in 90% of these cases (83% in 1989). Adjuvant chemotherapy was given to 92% of premenopausal women with node-positive disease and 63% with poor-prognosis node-negative tumours (v 78% and 14%, respectively, in 1989). Among postmenopausal women with receptor-positive tumours, tamoxifen was prescribed for 91% of those with positive nodes (85% in 1989) and 79% of those with negative nodes (30% in 1989). Among postmenopausal women with receptor-negative tumours, chemotherapy was prescribed for 70% with positive nodes (v 33%) and 58% with negative nodes (v none). Conclusions: Patterns of management of women with early invasive breast cancer in Western Australia during the 1990s changed significantly in all respects toward those recommended in the 1995 guidelines.